1. Technical Field
The present invention relates to a high-pressure liquefied extract of marine algae for producing bioethanol under high pressure and a method of producing the same and, more particularly, to a method of producing a liquid extract from marine algae under high pressure and of producing bioethanol from the liquid extract by fermentation with yeast.
2. Background Art
Development of alternative energy has become a global topic on the background of high oil prices, energy security, and tight restriction on greenhouse gas emissions with that bioethanol supply, the next generation fuel, is under rapid development world-wide. The Bush administration proclaimed that they will increase the use of alternative energy such as bioethanol and reduce 20% of oil consumption by 2017, and Japan, China, and ASEAN nations are promoting policies on the expansion of bioethanol production.
Bioethanol is a fuel extracted from plants such as sugar cane and corn. In addition to biodiesel, bioethanol comes into the spotlight as a representative renewable energy resource because bioethanol can be used solely or mixed with gasoline as a fuel for vehicles. Moreover, bioethanol reduces dependence on imports of crude oil. Carbon dioxide emitted during combustion of bioethanol is an exception in the calculation of greenhouse gas emissions provided in the Kyoto Protocol so that reduction of greenhouse gas emissions can be achieved. Unlike any other clean fuel for which there is a need to build up infrastructure (such as a fueling station) for supply, bioethanol supply is possible with an existing infrastructure (such as a gas station), so that early commercial use of bioethanol is possible. As such, the production of bioethanol is gradually increasing with an increase of the demand and interest for bioethanol.
However, since bioethanol is emerging as an alternative energy, the demands for corn, sugar cane, and wheat which are raw material for bioethanol are rapidly increased. This is one of the factors causing the surge in grain prices.
Especially, it is expected that the use of a competitive agricultural products such as corn which is a raw material for the production of ethanol is increased, thus the production expansion of bio-fuel is causing an increased demand for corn. The expanding demand for corn is likely to cause rising costs for beverage and food makers in which grain is used as raw materials, and for cattle and poultry farmers. Consequently, it is anticipated that consumer prices of food and livestock products will increase. The method of producing bioethanol from grain cannot be free itself from the problem of the surge in grain prices as well as criticism that grain resources could be used as food for starving people.
Hereupon, the world market of bioenergy is looking to shift its source from grain ethanol to cellulosic ethanol, but lignin removal in the process for the production of cellulosic ethanol is a problem and a breakthrough related thereto has not yet been found.
Recently, some research groups at home and abroad are developing a technique producing bioethanol from carbohydrate and saccharide-rich marine algae. Marine algae has higher economic effects in harvest frequencies, crop yields per unit land area, carbon dioxide absorption power per unit land area, energy yield, and production costs per liter than other raw materials such as grain and wood, and has relatively less negative factors such as destruction of food resources and nature. When marine algae which abnormally overgrowth due to eutrophication of sea water and pollutes sea water is used as a raw material for producing bioethanol, economical and environmentally friendly advantages such as converting waste materials into value added products are expected.
Production of bioethanol requires three steps; a saccharification of a raw material, a fermentation, and a distillation. Pretreatments such as a chemical treatment, a thermal treatment, and an enzyme treatment are used in the saccharification process. However, these pretreatments have disadvantages such as a low yield, changes of components, corrosion of the equipments by additives, environmental pollution, and production of useless by-products. No results having commercial possibilities have been reported yet. Moreover, growth of yeast used in a fermentation process is inhibited by the produced alcohol so that efficiency of bioethanol production becomes inferior.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.